Gulls, Larus spp., Foraging at Pink Salmon, Oncorhynchus gorbuscha, Spawning Runs

Small and immature gulls foraged more often on drifting salmon eggs than did large and mature gulls, and large and mature gulls foraged more often on salmon carcasses, at streams in Southeast Alaska. These differences may be related to body size via physical strength and dominance status, as well as foraging experience

Seed Dispersal by Brown Bears, Ursus arctos, in Southeastern Alaska

Mammals often consume fleshy fruits and disperse significant quantities of the enclosed seeds. In southeastern Alaska, Brown Bears (Ursus arctos) are among the most important dispersers of seeds for the numerous plant species producing fleshy fruits, because these bears are abundant, often eat large quantities of fruit, and commonly excrete seeds in germinable condition. Scat analyses showed that Brown Bears on Chichagof Island ate increasing quantities of fruit through summer and fall. Scats commonly contained several thousand seeds, often of two or more species. Four kinds of seeds of fleshyfruited plants that normally grow in forest understory germinated at similar levels when experimentally deposited (in bear scats) in the two most common habitats (forest and muskeg), suggesting that habitat distribution of these plants is not determined simply by germination patterns. Although seed passage through bear digestive tracts and the composition of scats are known to affect germination rates to some degree, the most important role of bears in seed dispersal is probably transport

The Effect of Temperature and Light Upon the Phenotypes of Some Collembola

Of five species reared under different conditions of temperature and light, only Hypogastrura matura exhibited a phenotypic difference. This difference was in the relative lengths of the furcula and the head and appeared to be a matter of selective survival rather than a direct response of the phenotype to the environment

Permeability of anti-fouling PEGylated surfaces probed by fluorescence correlation spectroscopy

The present work reports on in situ observations of the interaction of organic dye probe molecules and dye-labeled protein with different poly(ethylene glycol) (PEG) architectures (linear, dendron, and bottle brush). Fluorescence correlation spectroscopy (FCS) and single molecule event analysis were used to examine the nature and extent of probe朠EG interactions. The data support a sieve-like model in which size-exclusion principles determine the extent of probe朠EG interactions. Small probes are trapped by more dense PEG architectures and large probes interact more with less dense PEG surfaces. These results, and the tunable pore structure of the PEG dendrons employed in this work, suggest the viability of electrochemically-active materials for tunable surfaces

Senda Darwin Biological Station: Long-term ecological research at the interface between science and society

Indexación: Web of Science; Scielo.La Estación Biológica Senda Darwin (EBSD) constituye un centro de investigación inmerso en el paisaje rural del norte de la Isla de Chiloé (42º S), donde fragmentos del bosque siempreverde original coexisten con praderas de uso ganadero, turberas de Sphagnum, matorrales sucesionales, plantaciones de Eucalyptus y otras formaciones de origen antropogénico. Desde 1994 hemos realizado estudios de largo plazo centrados en algunas especies de plantas (e.g., Pilgerodendron uviferum D. Don) y animales (e.g., Aphrastura spinicauda Gmelin, Dromiciops gliroides [Thomas]) catalogados como amenazados o escasamente conocidos y en ecosistemas nativos de importancia regional y global (e.g., turberas de Sphagnum, bosque Valdiviano y Nordpatagónico). Las investigaciones han considerado las respuestas de las especies y de los ecosistemas frente al cambio antropogénico del paisaje y cambio climático, así como los efectos de diferentes formas de manejo. Este escenario es semejante al de otras regiones de Chile y Latinoamérica lo que da generalidad a nuestros resultados y modelos. En este período, investigadores asociados a la EBSD han producido más de un centenar de publicaciones en revistas nacionales e internacionales y 30 tesis de pre y postgrado. Entendiendo el papel clave de los seres humanos en los procesos ecológicos de la zona rural, la EBSD ha desarrollado un programa de educación ecológica y vinculación del avance científico con la sociedad local y nacional. La integración de la EBSD a la naciente red de Sitios de Estudios Socio-Ecológicos de Largo Plazo en Chile consolidará y fortalecerá la investigación básica y aplicada que realizamos para proyectarla hacia la siguiente década.Senda Darwin Biological Station (SDBS) is a field research center immersed in the rural landscape of northern Chiloé island (42º S), where remnant patches of the original evergreen forests coexist with open pastures, secondary successional shrublands, Sphagnum bogs, Eucalyptus plantations and other anthropogenic cover types, constituting an agricultural frontier similar to other regions in Chile and Latin America. Since 1994, we have conducted long-term research on selected species of plants (e.g., Pilgerodendron uviferum) and animals (e.g., Aphrastura spinicauda, Dromiciops glirioides) that are considered threatened, poorly known or important for their ecological functions in local ecosystems, and on ecosystems of regional and global relevance (e.g., Sphagnum bogs, North Patagonian and Valdivian rain forests). Research has assessed the responses of species and ecosystems to anthropogenic land-use change, climate change, and the impact of management. During this period, more than 100 scientific publications in national and international journals, and 30 theses (graduate and undergraduate) have been produced by scientists and students associated with SDBS. Because of our understanding of the key role that humans play in ecological processes at this agricultural frontier, since the establishment of SDBS we have been committed to creative research on the communication of science to society and ecological education. The integration of SDBS to the nascent Chilean network of long-term socio-ecological research will consolidate and strengthen basic and applied research to project our work into the next decade.http://ref.scielo.org/vbm4r

Integrating Ecology and Environmental Ethics: Earth Stewardship in the Southern End of the Americas

This article discusses integrating ecology and environmental ethics

EphA4 Blockers Promote Axonal Regeneration and Functional Recovery Following Spinal Cord Injury in Mice

Upregulation and activation of developmental axon guidance molecules, such as semaphorins and members of the Eph receptor tyrosine kinase family and their ligands, the ephrins, play a role in the inhibition of axonal regeneration following injury to the central nervous system. Previously we have demonstrated in a knockout model that axonal regeneration following spinal cord injury is promoted in the absence of the axon guidance protein EphA4. Antagonism of EphA4 was therefore proposed as a potential therapy to promote recovery from spinal cord injury. To further assess this potential, two soluble recombinant blockers of EphA4, unclustered ephrin-A5-Fc and EphA4-Fc, were examined for their ability to promote axonal regeneration and to improve functional outcome following spinal cord hemisection in wildtype mice. A 2-week administration of either of these blockers following spinal cord injury was sufficient to promote substantial axonal regeneration and functional recovery by 5 weeks following injury. Both inhibitors produced a moderate reduction in astrocytic gliosis, indicating that much of the effect of the blockers may be due to promotion of axon growth. These studies provide definitive evidence that soluble inhibitors of EphA4 function offer considerable therapeutic potential for the treatment of spinal cord injury and may have broader potential for the treatment of other central nervous system injuries

Seed size variation: magnitude, distribution, and ecological correlates

We examined seed-mass variation in 39 species (46 populations) of plants in eastern-central Illinois, USA. The coefficient of variation of seed mass commonly exceeded 20%. Significant variation in mean seed mass occurred among conspecific plants in most species sampled (by hierarchical ANOVA), averaging 38% of total variance. For most species, within-plant variation was the larger component of total variance, averaging 62% of total variance. Variation in seed mass among fruits within crops was significant in most species tested.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42741/1/10682_2005_Article_BF02067274.pd

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570